Active Fuel Management Valve Lifters
When operating in V8 mode, the dynamic fuel management valve lifters function similar to traditional valve lifters. The oil control solenoid valves are in the closed position, with no pressurized oil directed to the valve lifters. The pushrod (1) travels upward and downward to actuate the rocker arm and valve. The spring loaded locking pins (5) of the lifter are extended outward and mechanically lock the pin housing (4) to the outer body of the valve lifter (3).
When the dynamic fuel management system is commanded ON for a given cylinder, the ECM will direct the oil control solenoid valve, for that cylinder, to open and direct pressurized oil to the valve lifter. Oil travels through the oil control solenoid valve and bore and through a gallery that supplies oil pressure to the inlet port (6) of the valve lifter.
When an oil control solenoid valve is commanded open, pressurized oil forces the locking pins (11) inward. The pushrod (7) remains in a constant position and does not travel upward and downward. The outer body of the lifter (9) moves upward and downward independently from the pin housing (10). The valve lifter spring (8) retains tension on the valve train components to eliminate valve train noise.
When an oil control solenoid valve is commanded off, the oil pressure within the lifter will decrease and the locking pins will move outward to mechanically lock the pin housing and outer body.